There is now abundant evidence (from nmr, hydrogen-deuterium exchange, fluorescence spectroscopy and molecular dynamics calculations) that the traditional static view of a protein structure is inadequate to explain the relationship of structure and function in many cases. We have developed a method of extracting dynamic information from the normally static structure as revealed by x-ray crystallography. The method can show the conformational and vibrational motion of every atom in a crystalline protein. The object of this research proposal is to apply this new technique to myoglobin and cytochrome C in different states of ligandation, and to examine the effect on protein motion of the complexing of substrates and inhibitors with ribonuclease A.